Add api.structural.assign_product, assign_to_building, and api.geometry.add_topology_representation

assign_product creates IfcRelAssignsToProduct linking a structural member to
a physical building element. assign_to_building creates IfcRelServicesBuildings
linking a structural analysis model to a building. add_topology_representation
creates IfcTopologyRepresentation for structural elements, inferring the
representation type from the item class.

Generated with the assistance of an AI coding tool.

src/ifcopenshell-python/ifcopenshell/api/structural/assign_product.py

@@ -0,0 +1,64 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2026 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+# This file was generated with the assistance of an AI coding tool.
+
+import ifcopenshell
+import ifcopenshell.api.root
+
+
+def assign_product(
+    file: ifcopenshell.file,
+    relating_product: ifcopenshell.entity_instance,
+    related_object: ifcopenshell.entity_instance,
+) -> ifcopenshell.entity_instance:
+    """Links an object to a product via IfcRelAssignsToProduct
+
+    Typically used to associate a physical building element with a structural
+    analysis member (IfcStructuralSurfaceMember, IfcStructuralCurveMember) so
+    that analysis results can be traced back to the physical model.
+
+    :param relating_product: The IfcProduct that the object is assigned to,
+        typically an IfcStructuralMember.
+    :param related_object: The IfcObjectDefinition being assigned, typically
+        a physical building element such as an IfcWall or IfcSlab.
+    :return: The IfcRelAssignsToProduct relationship.
+
+    Example:
+
+    .. code:: python
+
+        wall = ifcopenshell.api.root.create_entity(model, ifc_class="IfcWall")
+        member = ifcopenshell.api.root.create_entity(
+            model, ifc_class="IfcStructuralSurfaceMember")
+        ifcopenshell.api.structural.assign_product(model,
+            relating_product=member, related_object=wall)
+    """
+    for rel in relating_product.ReferencedBy or []:
+        if not rel.is_a("IfcRelAssignsToProduct"):
+            continue
+        if related_object in rel.RelatedObjects:
+            return rel
+        related_objects = list(rel.RelatedObjects)
+        related_objects.append(related_object)
+        rel.RelatedObjects = related_objects
+        return rel
+
+    rel = ifcopenshell.api.root.create_entity(file, ifc_class="IfcRelAssignsToProduct")
+    rel.RelatingProduct = relating_product
+    rel.RelatedObjects = [related_object]
+    return rel